Basic and Clinical Studies on Development and Progression of the Human Osteosarcoma

1)Oncogene expression was studied in10lines of human osteosarcoma xenografts transplanted onto nude mice by southern and northern blotting techniques.C-myc was amplified in one line.At m-RNA level four lines expressed c-myc，four lines expressed c-H-ras and one line expressed c-fos。Osteosarcomas containing detectable c-myc transcripts grew more rapidly in nude mice than those with undetectable c-myc transcripts。Increased level of c-fos expression was associated with the high incidence of lung metastases of osteosarcoma in the transplanted nude mice。C-myc EJ-ras and E1A EJ-ras was introduced into the osteoblast cell line established from Wistar rat calvaria。The transfectants derived from the two separate transfections were morphologically transformed and made tumors in nude mice.2)Monoclonal antibody(MoAb)4E11 and MoAbs2D3，2H10were generated by immunizing Balb/c mice with a surgically obtained human osteosarcoma tissue and with a human osteosarcoma cell line respectively.……More These MoAbs reacted with eight human osteosarcoma tissues examined.MoAbs2D3 and 2H10 recognized bone specific alkaline phosphatase but not with alkaline phosphatase derived from liver，kidney，and small intestine.3)Ca binding protein，bone Gla-protein(BGP)was purified from human cortex bones，and five Mos were generated by immunizing Balb/c mice with this purified BGP.These MoAbs reacted with 27 human osteosarcoma tissues examined.Amino acid sequencing of the antigen indicated these MoAbs recognize human BGP.4)Four cell lines were established from human osteosarcoma xenografts transplanted onto nude mice.These cell lines constituted spheroids by Yuhas‘method。Growth of the spheroids were inhibited by x-ray irradiation，but the spheroids regrew eventually。Treatment of the spheroids with C‘-Ado before irradiation inhibited the regrowth.These data suggest that C‘-Ado treatment augments the radiosensitivity of osteosarcoma cells.5)Interaction between sarcoma cells and extracellular matrix was studied immunohistochemically in 14cases of human osteosarcoma tissue by using a panel of monoclonal antibodies against integrin beta1 family.Although fibronectin receptor(VLA4)was expressed in all cases，laminin receptors(VLA1，2，6)were rarely detected。VLA3was expressed more intense in the sarcoma cells invaded into surrounding normal tissues.These observations suggest that increased expression of a certain matrix receptor is associated with invasive capacity in sarcoma cells。Less：Less

1) Oncogene expression was studied in 10 lines of human osteosarcoma xenografts transplanted onto nude mice by southern and northern blotting techniques. C-myc was amplified in one line. At m-RNA level four lines expressed c-myc, four lines expressed c-H-ras and one line expressed cーfos. Osteosarcomas containing detectable c-myc transcripts grew more rapidly in nude mice than those with undetectable c-myc transcripts. Increased level of c-fos expression was associated with the high incidence of lung metastases of osteosarcoma in the transplanted nude mice. C-myc+EJ-ras and E1A+EJ-ras was introduced into the osteoblast cell line established from Wistar rat calvaria. The transfectants derived from the two separate transfections were morphologically transformed and made tumors in nude mice.2) Monoclonal antibody (MoAb) 4E11 and MoAbs 2D3, 2H10 were generated by immunizing Balb/c mice with a surgically obtained human osteosarcoma tissue and with a human osteosarcoma cell line respectively. … More These MoAbs reacted with eight human osteosarcoma tissues examined. MoAbs 2D3 and 2H10 recognized bone specific alkaline phosphatase but not with alkaline phosphatase derived from liver, kidney, and small intestine.3) Ca binding protein, bone Gla-protein (BGP) was purified from human cortex bones, and five MoAbs were generated by immunizing Balb/c mice with this purified BGP. These MoAbs reacted with 27 human osteosarcoma tissues examined. Amino acid sequencing of the antigen indicated these MoAbs recognize human BGP.4) Four cell lines were established from human osteosarcoma xenografts transplanted onto nude mice. These cell lines constituted spheroids by Yuhas' method. Growth of the spheroids were inhibited by x-ray irradiation, but the spheroids regrew eventually. Treatment of the spheroids with C'-Ado before irradiation inhibited the regrowth. These data suggest that C'-Ado treatment augments the radiosensitivity of osteosarcoma cells.5) Interaction between sarcoma cells and extracellular matrix was studied immunohistochemically in 14 cases of human osteosarcoma tissue by using a panel of monoclonal antibodies against integrin beta 1 family. Although fibronectin receptor (VLA4) was expressed in all cases, laminin receptors (VLA1,2, 6) were rarely detected. VLA3 was expressed more intense in the sarcoma cells invaded into surrounding normal tissues. These observations suggest that increased expression of a certain matrix receptor is associated with invasive capacity in sarcoma cells. Less